It is known that a filter tank is a requisite equipment for an aquarium to repeatedly filter water contained therein. However, most present filter tanks are fixed sizes which can not be varied according to the sizes of aquaria in which they are placed. Besides, in conventional aquaria, filter fibre pads are usually immersed in water which reduces filtration effect and causes undesirable death of fish. There is still a shortcoming commonly existing in present filter tanks, that is, there is not any warning mechanism to alarm users when the filter fibre pads lose their filtration function due to impurities deposited thereon, and consequently, users would have to frequently check the filter fibre pads for adequate filtration function. Therefore, a filter tank without warning mechanism would cause much inconvenience to users and has reverse effect on the safe living of fish.
It is therefore tried by the applicant to develop a prefab filter tank with warning function to eliminate the prior shortcomings existing in conventional filter tanks for aquaria.